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Diffraction blur with the R5 and four prime lenses

Started 7 months ago | Discussions thread
RogerZoul
RogerZoul Veteran Member • Posts: 3,243
Re: Diffraction blur with the R5 and four prime lenses

Karl_Guttag wrote:

RogerZoul wrote:

Seems like in the real world, or in real world use, you can get away with F11 using all of those lenses except maybe the 35mm.

Additionally, these were from the center of the image, which benefits the least from stopping down. I would expect that corners would peak at a somewhat higher f-number.

As a practical matter on most lenses, it does seem that there is only a slight fall-off due to diffraction between f8 and f11 but a more dramatic falloff going to f16 and beyond (you hit the knee of the diffraction curve). Certainly, as you stop down from wide open, the diffraction is getting worse, but this is usually offset by the improvements in other ways by stopping down. With top-notch lenses, you can see the image soften slightly in the center within one stop of wide open, but it is not dramatic as it gets between f11 and f16. With cheap zooms, you may have to go beyond f8 to peak the sharpness.

Good info, thanks!

 RogerZoul's gear list:RogerZoul's gear list
Canon EOS R5 Canon EF 500mm f/4.0L IS II USM Canon RF 35mm F1.8 IS STM Macro Canon RF 100-500mm F4.5-7.1L IS USM Canon RF 800mm F11 IS STM +31 more
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